OBD rejection problem on toyota fourrunner

Based on what you're describing, it sounds like your A/F Sensor (Air Filter Ratio Sensor) is bad.  The A/F sensor is similar to an O2 sensor in task but the A/F sensor detects a wider air/fuel ratio range than the O2 sensor, commonly found in newer model vehicles. Since you are having trouble starting up in the morning, my assumption is that your A/F sensor is bad, causing your 4Runner to not properly get up to temperature upon start up.  The other assumption is that your coolant system error (P0125) is a direct result from the A/F sensor being bad.  If your 4Runner can't get up to proper start temperature, it will cause your coolant system to malfunction.

I would replace your A/F sensor and see if your 4Runner throws either code again.  I think these run around $200.  If you want to be 100% sure, pull the sensor and run an ohm meter on it.  I'm not 100% sure what the required resistance is, I'll try to do some research and post it for you.

Matt

matt , thanks for the info, just to clarify it starts ok , it just shifts slowly out of first gear when cold

I agree with your findings and will invesigate this


you will get points for this for sure , but i want to leave this open for a bit to see what else gets posted

Thanks !!

The resistance between terminals +B and HT should be between 0.8 and 1.4 ohms at 68*F (20*C) on the A/F sensor.

I've seen occasions where the coolant temp sensor was faulty and constantly showed a cold state in the computer.  I believe this will keep the computer from going into closed loop mode needed for OBD emissions testing.  I don't remember the exact numbers for ohming out the ECT sensor, but you could probably find that in a haynes manual, and resistance varies depending on temperature.

Now, combining p0125 and P1135 could be multiple things.  Yes, it could be the A/F meter, but it can also be a faulty o2 sensor.

You have two o2 sensors per bank (4-cyl has a single bank, v6 has two banks), one before the catalytic convert (front) used to monitor A/F levels, and one after the cat (rear) to monitor the cat's efficiency.

Before buying sensors, I'd test the o2 sensor as well.  I forget the colors on the sensor wires, but they're are typically 4 wires, two solid color wires and two different color wires.  For instance, Bosch o2 sensors typically have two black wires for the heater and a white & a blue wire for the sensor.

You want to ohm out the sensor wires and it should be something between 10-20 ohms, maybe less, like 12-18, I don't remember exactly.  You'll want to test the primary o2 sensor before the cat on every bank.

The front & rear o2 sensors are different, so if/when ordering, make sure you get the correct one.  www.sparkplugs.com sometimes has better pricing than local stores like Autozone, Napa, or O'Reily.

Ha!  I kind of misread/misinterpreted something above.  When I saw A/F sensor, I was thinking of a MAF (mass air flow sensor), which lives before the throttle body and measures the amount of air that goes into intake.

Here, A/F is somewhat synonymous with o2 sensor, and the P1135 means is a manufacturer DTC for Toyota and reads "A/F Sensor Heater Circuit Malfunction Bank 1 Sensor 1".

I'm not sure if they go sensor 0 & 1, or 1 & 2, but I would think that's the front o2 sensor on the bank where cylinder 1 resides.

Sorry for any confusion.

Cougar, you got me in mid response.  Yes, the A/F sensor is synonymous with the O2 with A/F sensors being more prevalent in late model vehicles.

Michael- In regards to shifting, I'm not sure if that would be related to this problem or not.  When was the last time you changed your Transmission fluid?

You guys are awesome , I never expected such informative info!!

trans fluid change =never ! =will do ASAP

this may take a bit but I will to the testing you recomended and let you know the results

OK i am down loading the manual right now and will remove the mass airflow sensor, a friend of mine says that is would be a good idea to clean in with CRC MAF Sensor Cleaner that can be bought at advnace auto parts ,
I will post the results soon

Oh no... sorry, I didn't see this earlier.  You don't want to remove the MAF (Mass Air Flow Sensor), that has nothing to do with the code you are throwing.  You want to check the A/F Sensor which is in the same location as you would find the O2 sensor and test that.  Sorry I didn't catch the comment earlier, busy work day, hopefully you didn't get too far.

Sorry, I just realized I was supposed to give you the resistance numbers.  I have a 1998 4Runner, so the location of the A/F Sensor should be in the same place (3rd generation 4Runners are 1996-2002), on the tail pipe right before the catalytic converter.  The resistance should be 11-16 ohms, according to my repair manual.  

Let me know if you have any questions with this and/or the transmission flush, I just did a flush in mine a couple months ago.

Thanks
Matt

having trouble getting the connector to come apart , sprayed it with wd-40 to try to losten it up, i know you push the tab to the outside with a screwdriver and pull it apart right ?

Yeah , the a/f sensor shows no resistance at all , going to replace

any idea where to buy one ? looks like 170$ or so

http://www.ehow.com/how_4798712_clean-oxygen-sensor-toyota.html?ref=fuel&utm_source=yahoo&utm_medium=ssp&utm_campaign=yssp_art

i am going to try to clean it

No resistance, or infinite resistance?  No resistance is as if there's a direct short between the lines and ohm meter goes to zero, and infinite resistance means no connection at all.

If you're getting either of those readings, it's toast.

Any autoshop or dealer will have it (or they can special order it for you).  You will normally spend more at an autoshop.  $170 is about right, $200 is the average price you will find for the sensor and it's about time to replace it, 80,000 miles is the recommended replacement time period.

Sorry, I meant dealer, you'll spend more money at a dealer.

Sparkplugs.com *might* have it.

OK i got the A/F sensor on Amazon for about 160 that is about 90 cheaper than the autoparts store

i replaced it (got brand new nuts from the toyota dealer ) and went to advanced auto and borrowed the ODBII ,plugged it in and cleared the codes and it LOOKS GOOD no codes came back .I tried several times and started the engine and stoped , tried again and no codes came back , the OBDII reader said I should have the engine off with the key on the on position , I did this and still no codes ! well I dropped it of at the inspection station and we will see tomorow
MATT: you were right about the trans flush , I did it and now it shifts smooth !!

I will update this after the emmisions

oh and there is not any trouble light on the dash anymore either

crap , apperenty you have to drive it for 100 miles or so after you reset the codes

the emmisions station told me to take it for a drive and come back

Yeah, it has to complete so many cycles before the OBD will give an all clear.  That way people can't just clear the codes and go in for inspection in emissions controlled locations.

cougar , I never thought of the reason that makes since , well I am going to get off work early and take it out on the interstate to Front Royal and back , the reginstration is expired so maybe this is the safest way to drive it???

yeha drove it 100 miles and still OBD has some NOT READY issues, tempature cycle it a few times is what I am thinking , start it up warm up ,cool off , ect . still not any trouble lights

yeah i tryied it today and still no ready , i will drive it more

have you checked the coolant sensor its usally in the rad.